The present invention relates generally to systems and methods for monitoring air pressure and flow along pressurized telecommunications cable routes. More specifically, the present invention relates to index ranking systems and methods for monitoring air pressure and flow along pressurized telecommunications cable routes.
Each year, telecommunications companies spend large amounts of money pumping air into their cables and pipes which carry and enable the transmission of voice and data information. This low-humidity air creates positive pressure in the cables, enabling them to resist standing water, moisture damage, and the like. Such standing water and moisture damage may lead to noise on the line, data transmission errors, and, ultimately, complete cable failure.
The cables which make up a telecommunications network typically include a sheath made of a water-resistant or waterproof material, such as lead or polyethylene. These sheaths typically encompass wires, such as copper wires, and an insulation material which separates individual conductor pairs. This insulation material may be, for example, paper, pulp, or plastic.
Exposure of the interior of a cable to water or moisture may lead to a number of problems. For example, exposure of the interior of a cable to moisture may destroy the insulating characteristics of the paper or pulp. If cracks develop in the sheath of a cable or the sheath of a cable is sliced, water may enter the cable and electrolysis may occur, resulting in faulted conductor pairs. Thus, the basic premise of cable pressurization is to keep the pressure within a cable in excess of the pressure which could be applied by standing water. To this end, telecommunications companies and related industry associations have established minimum air pressure standards for underground, direct-buried, and aerial cables. For example, a minimum air pressure of six (6) pounds per square inch (PSI) may be required for underground cables, a minimum air pressure of three (3) PSI may be required for direct-buried cables, and a minimum air pressure of one (1) PSI may be required for aerial cables, as they are less at risk from water damage.
The air pumped into pressurized telecommunications cables originates from a plurality of air compressors, typically located in a company""s xe2x80x9ccentral officesxe2x80x9d or other facilities. These air compressors are preferably coupled with dryers or dehumidifiers operable for removing residual moisture from the air. Because a pressurized cable route may include a plurality of discrete sections of cable, each potentially thousands of feet long, the air pressure tends to decrease as the distance from a central office, and a given air compressor, increases. This pressure drop is due, in part, to the presence of inevitable leaks. Therefore, air pressure is typically re-established along a cable route by running an air pipe along the route and introducing air at a plurality of fixed points. The air pipe is connected to a plurality of manifolds which distribute air to the cables at, for example, each utility hole, making these connections easier to maintain.
In order to maintain a pressurized cable route, a plurality of air pressure and flow monitoring devices or sensors are placed at strategic points along the route (for example, at each manifold). These sensors are typically standard pressure transducers. The air pressure sensors measure the amount of air compression in a given cable volume at a given time in PSI. The flow sensors measure the standard cubic feet of air to pass through a given cable volume in a given period of time in standard cubic feet per hour (SCFH) or standard cubic feet per day (SCFD). Both the air pressure sensors and the flow sensors are linked to monitors in the various central offices so that readings may be taken by maintenance technicians at predetermined times. If the air pressure or flow level for a given sensor drops below a predetermined value, an alarm is tripped. A maintenance technician may then be dispatched to repair the affected cable, air pipe, manifold, etc.
Those who manage the pressurized cable route may collect data from the various central offices and, using existing software programs, analyze maintenance expenditures, track maintenance technician efficiency, identify problems, and rate overall pressurization system quality. This is typically done hierarchically, e.g., by region, district, office, area, and the like. These software programs, such as that used by GTE (the xe2x80x9cGTE Air Pressure Status Reportxe2x80x9d), typically generate summary information related to such items as the number of air pressure and flow alarms for a given period of time, the number of maintenance technician dispatches for a given period of time, a pressurization system quality index (SQI), the total man-hours for a given period of time or per sheath-mile, the operation of given air compressors or dryers, and problem regions, districts, offices, areas, etc. Although marginally useful, this information is typically complex, often inaccurate, and generally expensive to collect. More importantly, this information is dependent upon the schematics of a given pressurized telecommunications cable route, and must take the network layout into account. Thus, what is needed are simple index ranking systems and methods which provide inexpensive and accurate summary information related to the air pressure and flow performance of various regions, districts, offices, and areas.
The present invention provides index ranking systems and methods which take into account such factors as the number of air pressure sensors and flow sensors along a pressurized telecommunications cable route, the number of air pressure and flow alarms which are tripped during a given period of time, and the number of sensors which are inoperable at a given time.
In one embodiment, a method for monitoring the pressurization performance of a telecommunications cable network according to the present invention includes monitoring a plurality of pressurization sensors, monitoring a plurality of pressurization alarms, receiving data related to the plurality of pressurization sensors and the plurality of pressurization alarms, and generating an index. The index takes into account the number of pressurization sensors monitored during a predetermined period of time, the number of pressurization sensors which are inoperable during the predetermined period of time, and the number of pressurization alarms which are tripped during the predetermined period of time.
In another embodiment, a system for monitoring the pressurization performance of a telecommunications cable network according to the present invention includes a plurality of pressurization sensors, a plurality of pressurization alarms, a computer network operable for communicating data related to the plurality of pressurization sensors and the plurality of pressurization alarms, and an index ranking module. The index ranking module is operable for receiving the data communicated by the computer network and generating an index, wherein the index takes into account the number of pressurization sensors monitored during a predetermined period of time, the number of pressurization sensors which are inoperable during the predetermined period of time, and the number of pressurization alarms which are tripped during the predetermined period of time.
In a further embodiment, a computer-readable medium having executable commands operable for monitoring the pressurization performance of a telecommunications cable network includes executable commands operable for monitoring a plurality of pressurization sensors, monitoring a plurality of pressurization alarms, receiving data related to the plurality of pressurization sensors and the plurality of pressurization alarms, and generating an index. The index takes into account the number of pressurization sensors monitored during a predetermined period of time, the number of pressurization sensors which are inoperable during the predetermined period of time, and the number of pressurization alarms which are tripped during the predetermined period of time.
Advantageously, the index ranking systems and methods of the present invention provide cheap and accurate summary information related to the air pressure and flow performance of various regions, districts, offices, and areas. More importantly, the information provided by the systems and methods of the present invention is independent of the schematics of a given pressurized telecommunications cable route.